1. Field of the Invention
This invention relates to a target and more particularly to an aerial target.
2. Description of the Prior Art
The target drone of the present invention is related to the target drone shown in a pending application, Ser. No. 06/590,384, filed Mar. 16, 1984, jointly invented by John S. Attinello and David G. Rousseau, entitled Low-Cost, Expendable Crushable Target Aircraft, and is, in part, an improvement thereof.
It is important that weapons crews and weapons systems be realistically tested in order to verify operational readiness. A major element of testing for anti-missile and anti-aircraft crews and weapons is determination of their ability to hit targets flying on a converging course with the weapons platform. In reality, missiles and aircraft on such a course would present a critical threat to the weapons platform. In addition, some current weapons systems, which operate automatically using radar and a computer, "ignore" nonconverging targets as non-threatening. Equally important, however, is determination of ability to hit targets flying by the weapons platform, i.e., targets simulating that large number of missiles and aircraft which, in reality, would be converging on distant points. An ideal target for testing purposes is one that both operates realistically and responds vividly to a hit so that determination of crew and weapon effectiveness can be readily and accurately measured.
A variety of targets have been used to test anti-aircraft and anti-missile weapons and the crews which operate those weapons. One type of target used is a target device towed by a non-target aircraft. An example of this type of target is shown in U.S. Pat. No. 3,128,468. This device comprises a hollow foam shell with means for introducing air under pressure to prevent collapse under aerodynamic loads. A shortcoming of this type of device is that it cannot simulate a converging threat, i.e., safety considerations dictate that the device cannot converge on the weapons platform because of risk that the towing aircraft will be struck by weapons fire. Hence, this device cannot be used to "trigger" an automatic system. Another shortcoming of this device is its lack of guidance system. A typical towing cable is 20,000 feet long. With the cable fully extended, there is a large envelope in which towed targets maneuver. In the past, towing cables have broken, been severed by weapons fire, or simply not kept targets sufficiently aloof. Subsequently, targets have struck or been dragged across weapons platforms causing considerable damage. Backup guidance systems can reduce the possibility of damage caused by a loose or insufficiently elevated target. Further, this type of device is not realistic because it does not behave realistically when struck by weapons fire. Whereas an actual missile or aircraft can be caused to explode and/or to lose sufficient structural integrity to remain airborne when struck by weapons fire, this type of target does not explode and remains airborne behind the towing craft notwithstanding number of hits made on or amount of damage sustained by the target.
A second type of target employed is an unmanned, self-propelled target aircraft, i.e. a drone. Since no towing craft is employed, a drone overcomes the shortcomings of towed targets, mentioned above, and provides a more suitable target to simulate an enemy aircraft or missile on a converging course with the weapons platform. An example of this type of target is shown in the pending application, identified above. This device was invented to replace drones which were heavier (approximately twenty times), more expensive (approximately twenty-six times), and comprising elements that presented a serious hazard upon impact (e.g., aluminum parts, fiberglass parts, and a jet engine), especially impact with a weapons platform during training. This device comprises a target body formed from crushable lightweight foamed material, a solid propellant rocket motor made of a non-metallic lightweight material, a guidance sensor, and a guidance system.
Although the target drone disclosed in the pending application, identified above, effectively overcame all the cost and safety shortcomings of the prior art for a target drone to simulate a converging threat, the target drone disclosed by the pending application is not without a shortcoming. The "soft" nature of this drone makes it virtually invisible to bullets or similar projectiles being fired at it. Whereas if fire from a weapons system hits the warhead of an actual missile, the warhead explodes and destroys the missile, bullets and similar projectiles can pass through this drone without causing catastrophic damage or stopping flight. It is possible for this drone to sustain multiple hits without losing its structural integrity. The drone's unresponsiveness to "hits" hampers determination of a weapons system's effectiveness in striking threatening targets and makes testing less realistic. Certain embodiments of the target of the present invention, although they retain all the advantages and features of the forms of the target described in the pending application, represent a decided advance in the art as they will burst when hit by weapons systems fire.
Other target vehicles have been devised which are frangible, such as are shown in U.S. Pat. Nos. 3,311,324 and 3,128,463. U.S. Pat. No. 3,311,324 teaches use of a remotely-controlled destruct system of a type adapted for explosively severing one wing from a damaged target or drone-aircraft to cause the target to fall within a prescribed impact area. While such a mechanism could be used to abort a drone gone astray, such a mechanism would not necessarily enhance drone responsiveness to hits. Also, this drone is actually less safe than the drone disclosed in the pending application for simulating a converging threat as it carries an explosive charge. Current high electromagnetic interference (EMI) environments surrounding ships and on battlefields render radio control unreliable. There would be a risk that such a drone could strike a ship or weapons implacement in training with the explosive intact and armed. Further, the destruct mechanism comprises metal brackets and pins which would become lethal projectiles upon impact as would other solid parts of the device. Still further, this drone comprises elements which make it much more expensive than the drone disclosed in the pending application.
Another frangible target device is shown in U.S. Pat. No. 3,128,463, described above. Although this towed device cannot safely simulate a converging threat, particularly on an automatic system, it can safely simulate an enemy aircraft or missile converging on a distant point. Fire is properly directed to the side of the target rather than being directed towards it head on. This device is unrealistic as is because it is frangible only in event of impact with the towing craft and not frangible in in case of impact by a testing round. It is worth noting, however, that provided it could be made to behave realistically when struck by weapons fire, its value as a testing target would be significantly enhanced.